Autonomous driving control system for vehicle

ABSTRACT

An autonomous driving control system for a vehicle which is able to switch between manual driving and autonomous driving is provided with a driver condition sensor, acting part, and electronic control unit. The electronic control unit is provided with an autonomous driving control part, reliance calculating part for calculating an autonomous driving output reliance, vigilance calculating part for calculating a driver vigilance, and an action control part for controlling a strength of an action against a driver. In a region in which an operating point determined by the autonomous driving output reliance and driver vigilance can fall, a plurality of sub regions are defined by boundary lines extending so that the driver vigilance becomes higher as the autonomous driving output reliance becomes lower. The action control part controls the strength of the action against the driver to differ in accordance with the sub region in which the operating point falls.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an autonomous driving control systemfor a vehicle.

2. Related Art

It is known in the art an autonomous driving control system for avehicle which is able to switch between manual driving and autonomousdriving. The system is provided with an autonomous driving control partfor controlling autonomous driving, a recognizing part for recognizingan awakeness of a driver, and an alarm part for prompting the driver toawake if the recognized awakeness is lower than a predetermined level(for example, see Japanese Patent Publication No. 6-171391A).

SUMMARY OF INVENTION

In this regard, while explained in detail later, to which extent theautonomous driving of the vehicle can be suitably performed, that is, towhat extent an output of the autonomous driving control part can berelied on, is not necessary constant. Specifically, in a case where theautonomous driving control part for example uses signals from a GPS(Global Positioning System) to localize a host vehicle and performsautonomous driving based on the localization result, if the signals fromthe GPS can be received well, the autonomous driving control part canaccurately localize the host vehicle and, therefore, can suitablyperform autonomous driving. That is, at this time, a reliance of theoutput of the autonomous driving control part is high. As opposed tothis, if it is difficult to receive the signals from the GPS well dueto, for example, a terrain around the host vehicle, etc., the autonomousdriving control part has difficulty in accurately localizing the hostvehicle and therefore has difficulty in suitably performing autonomousdriving. In other words, the reliance of the output of the autonomousdriving control part at this time is low.

If the reliance of the output of the autonomous driving control part islow, the awakeness of the driver must be high in order to prepare formanual driving. Conversely, if the reliance of the output of theautonomous driving control part is high, the low awakeness of the driveris allowable.

However, Japanese Patent Publication No. 6-171391A mentioned above doesnot refer to the reliance of the output of the autonomous drivingcontrol part at all. For this reason, even if the reliance of the outputof the autonomous driving control part is high, the awakeness of thedriver is maintained higher than the predetermined level. As a result,the driver is liable to be maintained in an excessively tense state. Onthis point, if setting the above predetermined level low, the awakenessof the driver is maintained low and the problem of the driver beingexcessively tense may be able to be eliminated. However, in this case,if the reliance of the output of the autonomous driving control partfalls for some sort of reason, the awakeness of the driver at this timeis low. Thus, the driver may not be ready for manual drivingsufficiently and therefore the driver is liable to be confused.

Therefore, if referring to a vigilance of the driver for autonomousdriving as a driver vigilance, an object of the present invention is toprovide an autonomous driving control system for a vehicle which is ableto suitably maintain the driver vigilance, regardless of the autonomousdriving output reliance.

According to one embodiment of the present invention, there is providedan autonomous driving control system for a vehicle which is able toswitch between manual driving and autonomous driving, the systemcomprising: a driver condition sensor for detecting a condition of adriver; an acting part able to take an action against the driver; and anelectronic control unit comprising: an autonomous driving control partconfigured to control the autonomous driving; a reliance calculatingpart configured to calculate an autonomous driving output relianceexpressing a reliance of an output of the autonomous driving controlpart; a vigilance calculating part configured to calculate a drivervigilance expressing a vigilance of the driver for the autonomousdriving based on the condition of the driver detected by the drivercondition sensor; and an action control part configured to control theacting part to control a strength of an action against the driver,wherein, in a region in which an operating point determined by theautonomous driving output reliance and the driver vigilance can fall, aplurality of sub regions are defined by at least one boundary lineextending so that the driver vigilance becomes higher as the autonomousdriving output reliance becomes lower, and wherein the action controlpart is configured to control the strength of the action against thedriver to differ in accordance with the sub region in which theoperating point falls.

According to another embodiment of the present invention, there isprovided an autonomous driving control system for a vehicle which isable to switch between manual driving and autonomous driving, the systemcomprising: a driver condition sensor for detecting a condition of adriver; an acting part able to take an action against the driver; and anelectronic control unit comprising: an autonomous driving control partconfigured to control the autonomous driving; a reliance calculatingpart configured to calculate an autonomous driving output relianceexpressing a reliance of an output of the autonomous driving controlpart; a vigilance calculating part configured to calculate a drivervigilance expressing a vigilance of the driver for the autonomousdriving based on the condition of the driver detected by the drivercondition sensor; a target vigilance calculating part configured tocalculate a lower limit target vigilance, which is a lower limit targetof the driver vigilance, based on the autonomous driving outputreliance, the lower limit target vigilance becoming higher as theautonomous driving output reliance becomes lower; an vigilance deviationcalculating part configured to calculate a vigilance deviation which isa deviation of the driver vigilance with respect to the lower limittarget vigilance; and an action control part configured to control theacting part to control a strength of an action against the driver,wherein the action control part is configured to control the strength ofthe action against the driver so as to: maintain the driver vigilanceequal to or higher than the lower limit target vigilance; and differ inaccordance with the vigilance deviation.

According to still another embodiment of the present invention, there isprovided an autonomous driving control system for a vehicle which isable to switch between manual driving and autonomous driving, the systemcomprising: a driver condition sensor for detecting a condition of adriver; a display part which the driver can view; and an electroniccontrol unit comprising: an autonomous driving control part configuredto control the autonomous driving; a reliance calculating partconfigured to calculate an autonomous driving output reliance expressinga reliance of an output of the autonomous driving control part; avigilance calculating part configured to calculate a driver vigilanceexpressing a vigilance of the driver for the autonomous driving based onthe condition of the driver detected by the driver condition sensor; anda display control part configured to control the display part to displaythe autonomous driving output reliance and the driver vigilancesimultaneously on the display part.

The present invention may be more fully understood from the descriptionof the preferred embodiments according to the invention as set forthbelow, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a view showing a block diagram of an autonomous drivingcontrol system for a vehicle of a first embodiment according to thepresent invention.

FIG. 2 is a schematic view for explaining an external sensor of thefirst embodiment according to the present invention.

FIG. 3 is a schematic view for explaining an internal sensor of thefirst embodiment according to the present invention.

FIG. 4 is a view showing a block diagram of an autonomous drivingcontrol part of the first embodiment according to the present invention.

FIG. 5 is a schematic view for explaining a function of an autonomousdriving control part.

FIG. 6 is a view showing a map of sub regions.

FIG. 7 is a view for explaining action control of the first embodimentaccording to the present invention.

FIG. 8 is a view for explaining action control of the first embodimentaccording to the present invention.

FIG. 9 is a view showing a map of a strength of an action against adriver.

FIG. 10 is a flow chart showing an action control routine of the firstembodiment according to the present invention.

FIG. 11 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 12 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 13 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 14 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 15 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 16 is a view showing a map of sub regions of another embodimentaccording to the present invention.

FIG. 17 is a view showing a block diagram of an autonomous drivingcontrol system for a vehicle of a second embodiment according to thepresent invention.

FIG. 18 is a view showing a map of a lower limit target vigilance.

FIG. 19 is a view explaining action control of the second embodimentaccording to the present invention.

FIG. 20 is a view showing a map of a strength of an action against adriver.

FIG. 21 is a view showing a map of a strength of an action against adriver.

FIG. 22 is a flow chart showing an action control routine of the secondembodiment according to the present invention.

FIG. 23 is a view showing a block diagram of an autonomous drivingcontrol system for a vehicle of a third embodiment according to thepresent invention.

FIG. 24 is a schematic view showing one example of display on a displaypart of the third embodiment according to the present invention.

FIG. 25 is a view explaining a display function of the third embodimentaccording to the present invention.

FIG. 26 is a view explaining a display function of the third embodimentaccording to the present invention.

FIG. 27 is a view explaining a display function of the third embodimentaccording to the present invention.

FIG. 28 is a view explaining a display function of the third embodimentaccording to the present invention.

FIG. 29 is a flow chart showing a display control routine of the thirdembodiment according to the present invention.

FIG. 30 is a schematic view showing another example of display on adisplay part.

FIG. 31 is a schematic view showing another example of display on adisplay part.

FIG. 32 is a schematic view showing another example of display on adisplay part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a block diagram of an autonomous driving control system fora vehicle of a first embodiment according to the present invention.Referring to FIG. 1, the autonomous driving control system for a vehicleis provided with an external sensor 1, GPS receiving part 2, internalsensor 3, map database 4, storage device 5, navigation system 6, HMI(human machine interface) 7, actuator 8, driver condition sensor 9,acting part 10, and electronic control unit (ECU) 20.

The external sensor 1 is a detection device for detecting information onan outside or surroundings of a host vehicle. The external sensor 1 isprovided with at least one of a LIDAR (laser imaging detection andranging), radar, and camera. In the first embodiment according to thepresent invention, as shown in FIG. 2, the external sensor 1 is providedwith a LIDAR SO1, radar SO2, and camera SO3.

The LIDAR SO1 is a device for detecting a road over which the hostvehicle is running or at least one outside object using laser beams. Inthe example shown in FIG. 2, the LIDAR SO1 is installed on a roof of avehicle V. The LIDAR SO1 successively fires laser beams toward theentire surroundings of the host vehicle V and measures distances to theroad and object(s) from reflected lights to detect the road andobject(s) around the host vehicle V in the form of a 3D image. The 3Dimage of the road and object(s) detected by the LIDAR SO1 is transmittedto the electronic control unit 20. On the other hand, a radar SO2 is adevice for detecting at least one object outside the host vehicle Vusing electromagnetic waves. In the example shown in FIG. 2, the radarsSO2 are attached to bumpers at the front and rear of the vehicle V. Theradars SO2 emit electromagnetic waves from the radars SO2 to thesurroundings of the host vehicle V and measure a distance to theobject(s) in the surroundings of the host vehicle V from the reflectedwaves. The object information detected by the radars SO2 is sent to theelectronic control unit 20. The camera SO3, in the example shown in FIG.2, is provided with a front camera provided at an inside of a frontglass of the vehicle V. The front camera SO3 captures a color image ofan area in front of the host vehicle V. The color image informationobtained by the front camera SO3 is transmitted to the electroniccontrol unit 20. Note that, as explained above, the LIDAR SO1 and radarsSO2 measure the distances to the object(s) around the host vehicle V.Therefore, one or both of these may also be referred to as a distancemeasurement sensor.

Referring again to FIG. 1, the GPS receiving part 2 receives signalsfrom three or more GPS satellites to thereby detect the absolutelocation of the host vehicle V (for example, the latitude and longitudeof the host vehicle V). The absolute location information of the hostvehicle V detected by the GPS receiving part 2 is transmitted to theelectronic control unit 20.

The internal sensor 3 is a detection device for detecting a runningstate of the host vehicle V. The running state of the host vehicle V isexpressed by at least one of a speed, acceleration, and attitude of thehost vehicle. The internal sensor 3 is provided with one or both of avehicle speed sensor and IMU (inertial measurement unit). In the firstembodiment according to the present invention, the internal sensor 3 isprovided with the vehicle speed sensor and IMU. The vehicle speed sensordetects a speed of the host vehicle V. The IMU is provided for examplewith a three-axis gyro and a 3-direction acceleration sensor, anddetects a 3D angular speed and acceleration of the host vehicle V todetect the acceleration and attitude of the host vehicle V based onthese. The running state information of the host vehicle V detected bythe internal sensor 3 is transmitted to the electronic control unit 20.

The map database 4 is a database relating to map information. This mapdatabase 4 is stored for example in an HDD (hard disk drive) mounted inthe vehicle. The map information includes, for example, locationinformation on roads and information on road shapes (for example, curvedor straight, curvature of curves, locations of intersections, mergingpoints, and branching points, etc.).

The storage device 5 stores a 3D image(s) of the object(s) detected bythe LIDAR SO1, and a road map dedicated for autonomous driving which isproduced based on a result of detection by the LIDAR SO1. The 3Dimage(s) of the object(s) and road map are constantly or periodicallyupdated.

The navigation system 6 is a device for guiding the host vehicle V to adestination set by the driver of the host vehicle V through the HMI 7.This navigation system 6 calculates a target route up to the destinationbased on the current location information of the host vehicle V detectedby the GPS receiving part 2 and the map information of the map database4. The information on the target route of the host vehicle V istransmitted to the electronic control unit 20.

The HMI 7 is an interface for outputting and inputting informationbetween a passenger of the host vehicle V and the autonomous drivingcontrol system for the vehicle. In the first embodiment according to thepresent invention, the HMI 7 is provided with a display for displayingtext or image information, a speaker for emitting sound, and operatingbuttons or a touch panel for an input operation by the passenger.

The actuator 8 is a device for controlling driving operations of thehost vehicle V in accordance with control signals from the electroniccontrol unit 20. The driving operations of the vehicle V includepowering, braking, and steering of the vehicle V. The actuator 8 isprovided with at least one of a powering actuator, braking actuator, andsteering actuator. The powering actuator controls an output of an engineor electric motor providing a drive power of the vehicle V and therebycontrols the powering operation of the vehicle V. The braking actuatoroperates the braking system of the vehicle V and thereby controls thebraking operation of the vehicle V. The steering actuator operates asteering system of the vehicle V and thereby controls the steeringoperation of the vehicle V.

If the passenger operates the HMI 7 to start autonomous driving, asignal is sent to the electronic control unit 20 and autonomous drivingis started. That is, the driving operations of the vehicle V includingpowering, braking, and steering are controlled by the actuator 8. On theother hand, if the passenger operates the HMI 7 to stop autonomousdriving, a signal is sent to the electronic control unit 20, theautonomous driving is stopped, and manual driving, in which at least oneof the driving operations of the vehicle V is performed by the driver,is started. In other words, autonomous driving is switched to manualdriving. Note that, during autonomous driving, if the driver operatesthe vehicle V, that is, if the driver steers the vehicle, or if thedriver steps on the accelerator pedal, or if the driver steps on thebrake pedal, autonomous driving is switched to manual driving.Furthermore, if it is judged during autonomous driving that autonomousdriving would be difficult, manual driving is requested to the driverthrough the HMI 7.

The driver condition sensor 9 is a detection device for detecting acondition of the driver. The condition of the driver is expressed by,for example, one or both of an appearance and internal condition of thedriver. The appearance of the driver is expressed by, for example, atleast one of a line of vision of the driver, a state of eyelids of thedriver, a direction of a face of the driver, a posture of the driver,whether the driver is engaged in a second task, whether the driver isgripping the steering wheel, a distribution of pressure which the driverapplies to a seat of the vehicle V (a sitting pressure), and an amountof adjustment of the driver's seat. The posture of the driver isexpressed by whether arms of the driver are crossed or not, where handsof the driver are located, etc. The second task includes behaviors otherthan operations to drive the vehicle V, such as an operation of a mobilephone. The amount of adjustment of the driver's seat is expressed by aposition of the driver's seat, an angle of a back part of the seat, andother parameters able to be adjusted by the driver. On the other hand,the internal condition of the driver is expressed by, for example, aphysiological indicator such as heart rate, blood pressure, or skinpotential of the driver.

In a case where the condition of the driver is expressed by the line ofvision of the driver, the state of the eyelids of the driver, thedirection of the face of the driver, the posture of the driver, whetherthe driver is engaged in a second task, etc., the driver conditionsensor is provided with, for example, a driver camera attached to theinside of the vehicle V. This driver camera captures an image of thedriver. In the example shown in FIG. 3, the driver condition sensor 9 isprovided with a driver camera SD attached to an instrument panel of thevehicle V so as to face the driver D. In a case where the condition ofthe driver is expressed by whether the driver is gripping the steeringwheel, the driver condition sensor 9 is provided with, for example, acontact sensor attached to the steering wheel. This contact sensordetects, for example, whether the driver is gripping the steering wheelwith a gripping force higher than a predetermined set gripping force. Ina case where the condition of the driver is expressed by thedistribution of the sitting pressure, the driver condition sensor 9 isprovided with a sitting pressure sensor attached to the seat. Thissitting pressure sensor detects the distribution of the sittingpressure. In a case where the condition of the driver is expressed bythe state of the driver's seat, the driver condition sensor 9 isprovided with a seat status sensor attached to the seat. This seatstatus sensor detects the state of the driver's seat. In a case wherethe condition of the driver is expressed by the internal condition ofthe driver, the driver condition sensor 9 is provided with, for example,an internal condition sensor attached to the steering wheel. Thisinternal condition sensor detects, for example, the physiologicalindicator of the driver. The information on the condition of the driverdetected by the driver condition sensor 9 is transmitted to theelectronic control unit 20.

The acting part 10 is a device able to take an action against thedriver. The action against the driver includes, for example, at leastone of a visual action, audio action, and body sensory action. In a casewhere the action against the driver includes the visual action, theacting part 10 is provided with a display part able to be viewed by thedriver. The display part is provided with, for example, at least one ofa display for displaying text information or image information, lights,etc. In the example shown in FIG. 3, the acting part 10 is provided witha display A attached to the instrument panel of the vehicle V. Notethat, in the first embodiment according to the present invention, theacting part 10 and the HMI 7 are provided with a common display. Inanother embodiment according to the present invention (not shown), theacting part 10 and the HMI 7 are provided with respectively separatedisplays. On the other hand, in a case where the action against thedriver includes the audio action, the acting part 10 is provided with,for example, a speaker for emitting a sound or voice. In a case wherethe action against the driver includes the body sensory action, theacting part 10 is provided with, for example, at least one of a vibratorfor conveying vibration to the driver, a driver seat adjuster forchanging an angle or position of the seat of the driver, etc.

The acting part 10 can change a strength of the action against thedriver. That is, in a case where the acting part 10 is provided with adisplay, the action against the driver is strengthened by, for example,making a frequency of change of the image etc. displayed on the displayhigher, while the action is weakened by making this frequency lower.Alternatively, the action against the driver is strengthened by makingan interval of change of the image etc. shorter, while the action isweakened by making this interval longer. In a case where the acting part10 is provided with a speaker, the action against the driver isstrengthened by, for example, making the volume of the sound emittedfrom the speaker larger, while the action is weakened by making thevolume smaller. Alternatively, the action against the driver isstrengthened by making a frequency of the sound emitted from the speakerhigher while the action is weakened by making the frequency of thissound lower. In a case where the acting part 10 is provided with adriver seat adjuster, the action against the driver is strengthened by,for example, making the back part of the seat closer to a verticalorientation, while the action is weakened by making the back part closerto a horizontal orientation.

The electronic control unit 20 is a computer provided with componentsconnected with each other by a bidirectional bus such as a CPU (centralprocessing unit), ROM (read only memory), and RAM (random accessmemory). As shown in FIG. 1, the electronic control unit 20 of the firstembodiment according to the present invention is provided with a storagepart 21 having a ROM and RAM, autonomous driving control part 22,reliance calculating part 23, vigilance calculating part 24, and actioncontrol part 25.

The autonomous driving control part 22 is configured to controlautonomous driving of the vehicle. FIG. 4 shows a block diagram of theautonomous driving control part 22 of the first embodiment according tothe present invention. Referring to FIG. 4, the autonomous drivingcontrol part 22 of the first embodiment according to the presentinvention is provided with a plurality of control parts, that is, alocalizing part 22 a, object detecting part 22 b, moving/stationaryclassifying part 22 c, tracking part 22 d, integrated recognizing part22 e, traffic signal status recognizing part 22 f, and judgment/pathgenerating part 22 g. Next, referring to FIG. 5, functions of theautonomous driving control part 22 will be explained.

Referring to FIG. 5, to the localizing part 22 a, the information on arough location and attitude of the host vehicle V is input from the GPSreceiving part and IMU, and the information on an object referencepoint(s) around the host vehicle V is input from the distancemeasurement sensor. At the localizing part 22 a, the location andattitude of the host vehicle V are corrected based on these inputs androad map dedicated for autonomous driving stored in the storage device5. In one example, the location and attitude of the host vehicle V arecorrected so that the location(s) of the object reference point(s) inputfrom the distance measurement sensor matches the location(s) of theobject reference point(s) in the road map. That is, the information onthe corrected location and attitude of the host vehicle V is output fromthe localizing part 22 a.

On the other hand, to the object detecting part 22 b, the information onthe object reference point(s) around the host vehicle V is input fromthe distance measurement sensor, and the corrected location and attitudeof the host vehicle V is input from the localizing part 22 a. At theobject detecting part 22 b, the object(s) around the host vehicle V isdetected based on these inputs and the road map in the storage device 5.In one example, the object(s) is detected based on differences betweenthe object reference point(s) detected by the distance measurementsensor and the object reference point(s) in the road map. In anotherembodiment (not shown), the object(s) is detected based on whether ashape(s) of the object reference point(s) detected by the distancemeasurement sensor matches a shape(s) of a template(s) stored inadvance. That is, the information on the object(s) around the hostvehicle V is output from the object detecting part 22 b.

To the moving/stationary classifying part 22 c, the information on theobject(s) around the host vehicle V is input from the object detectingpart 22 b. At the moving/stationary classifying part 22 c, it isclassified if the object(s) is a moving object(s) or stationaryobject(s) based on this input and the road map in the storage device 5.The moving object(s) is an object(s) which can move, such as othervehicles, pedestrians, while the stationary object(s) is an object(s)which cannot move, such as buildings. That is, information on movingobject(s) and information on stationary object(s) are output from themoving/stationary classifying part 22 c.

To the tracking part 22 d, the information on the moving object(s) isinput from the moving/stationary classifying part 22 c. At the trackingpart 22 d, a movement(s) of the moving object(s) is tracked andsmoothened based on this input. That is, the information on thesmoothened movement(s) of moving object(s) is output from the trackingpart 22 d.

To the integrated recognizing part 22 e, the information on thecorrected location and attitude of the host vehicle V is input from thelocalizing part 22 a, the information on the stationary object(s) isinput from the moving/stationary classifying part 22 c, and theinformation on the smoothened movement(s) of the moving object(s) isinput from the tracking part 22 d. At the integrated recognizing part 22e, integrated outside environment information in which variousinformation on the outside environment of the host vehicle V integratedtogether is formed based on these inputs. The integrated outsideenvironment information includes, for example, information identifyingthe moving object(s) (for example, whether the moving object(s) is avehicle(s) or pedestrian(s)), information identifying the stationaryobject(s) (for example, whether the stationary object(s) is a stationaryvehicle(s) or building(s)) etc. That is, the integrated outsideenvironment information is output from the integrated recognizing part22 e.

To the traffic signal status recognizing part 22 f, the front colorimage is input from the front camera. At the traffic signal statusrecognizing part 22 f, information on a traffic signal in front of thehost vehicle V is identified. The information on the traffic signalincludes whether there is a traffic signal in front of the host vehicleV, whether the traffic signal is green, and other information. That is,the information on the state of the traffic signal is output from thetraffic signal status recognizing part 22 f.

To the judgment/path generating part 22 g, the information on thecorrected location and attitude of the host vehicle V is input from thelocalizing part 22 a, the integrated outside environment information isinput from the integrated recognizing part 22 e, the information on thesmoothened movement(s) of the moving object(s) is input from thetracking part 22 d, and the information on the state of the trafficsignal is input from the traffic signal status recognizing part 22 f. Atthe judgment/path generating part 22 g, various judgments are made basedon these inputs, the road map in the storage device 5, and the targetroute calculated by the navigation system 6, and information on thetarget path of the host vehicle V is generated. That is, the informationon the target path of the host vehicle V is output from thejudgment/path generating part 22 g.

The information on the target path output from the judgment/pathgenerating part 22 g, that is, the output of the autonomous drivingcontrol part 22, is input to the actuator 8. At the actuator 8, thedriving operations of the host vehicle V are controlled so that the hostvehicle V is driven in accordance with the target path.

Referring again to FIG. 1, the reliance calculating part 23 isconfigured to calculate an autonomous driving output reliance expressinga reliance of the output of the autonomous driving control part 22. Notethat, the autonomous driving output reliance is calculated in the formof a numerical value which changes continuously or in steps.

The vigilance calculating part 24 is configured to calculate a drivervigilance expressing a vigilance of the driver for the autonomousdriving based on the condition of the driver detected by the drivercondition sensor 9. Note that the driver vigilance is calculated in theform of a numerical value which changes continuously or in steps.

The action control part 25 is configured to control the acting part 10to control the strength of the action against the driver.

Now then, as explained above, the autonomous driving output relianceexpresses a reliance of the output of the autonomous driving controlpart 22. In the first embodiment according to the present invention, theoutput of the autonomous driving control part 22 is the output of thejudgment/path generating part 22 g, that is, the information on thetarget path, and thus the autonomous driving output reliance expresses areliance of the information on the target path. That is, for example, ifthe information on the target path is accurate, the autonomous drivingoutput reliance is higher, compared with if the information on thetarget path is inaccurate.

As explained while referring to FIG. 5, the output of the autonomousdriving control part 22, that is, the output of the judgment/pathgenerating part 22 g, is found based on the outputs of theabove-mentioned plurality of control parts 22 a, 22 b, 22 c, 22 d, 22 e,and 22 f. Therefore, the reliance of the output of the autonomousdriving control part 22, that is, the autonomous driving outputreliance, depends on the reliance of the outputs of the control parts 22a, 22 b, 22 c, 22 d, 22 e, and 22 f. Therefore, in the first embodimentaccording to the present invention, the autonomous driving outputreliance is calculated based on the reliance of at least one output ofthe plurality of control parts 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, and22 g.

Specifically, for example, if the output of the localizing part 22 a,that is, the information on the location and attitude of the hostvehicle V, is accurate, the reliance of the output of the localizingpart 22 a is higher and therefore the autonomous driving output relianceis higher, compared with if this information is inaccurate. In thiscase, for example, if the number of GPS satellites from which signalsare received is large, the output of the localizing part 22 a is moreaccurate compared with if the number of GPS satellites from whichsignals are received is small. Alternatively, if the GPS satellites fromwhich signals are received are positioned dispersed apart, the output ofthe localizing part 22 a is more accurate compared with if the GPSsatellites from which signals are received are positioned groupedtogether. Alternatively, if the number of information on the objectreference point(s) input from the distance measurement sensor is large,the output of the localizing part 22 a is more accurate compared with ifthe number of information on the object reference point(s) is small.Alternatively, if a difference(s) between the location(s) of the objectreference point(s) detected by the distance measurement sensor and thelocation(s) of the object reference point(s) in the road map is small,the output of the localizing part 22 a is more accurate compared with ifthe difference(s) is large.

Alternatively, if the output of the object detecting part 22 b, that is,the information on an object(s), is accurate, the autonomous drivingoutput reliance is higher compared with if the information isinaccurate. In this case, for example, if the number of location(s) ofthe object reference point(s) detected by the distance measurementsensor is large, the output of the object detecting part 22 b is moreaccurate compared with if the number of location(s) is small.Alternatively, if a sum of squares of difference(s) between thelocation(s) of object reference point(s) detected by the distancemeasurement sensor and the location(s) of the object reference point(s)in the road map is small, the output of the object detecting part 22 bis more accurate compared with if the sum is large. Alternatively, ifthe number of matching point(s) between a shape(s) of an objectreference point(s) detected by a distance measurement sensor and ashape(s) of a template is large, the output of the object detecting part22 b is more accurate compared with if the number of matching point(s)is small.

If the output of the moving/stationary classifying part 22 c, that is,the information on moving object(s) or the information on stationaryobject(s), is accurate, the autonomous driving output reliance is highercompared with if the information is inaccurate. In this case, forexample, if a ratio of the number of actually detected stationaryobject(s) with respect to the number of stationary object(s) stored inthe road map and able to be detected from the location of the hostvehicle V is high, the output of the moving/stationary classifying part22 c is more accurate compared with if the ratio is low. Alternatively,if a degree of match of a shape(s), volume(s), etc. of the movingobject(s) detected before a predetermined time and the shape(s),volume(s), etc. of the moving object(s) detected at the present time ishigh, the output of the moving/stationary classifying part 22 c is moreaccurate compared with if the extent of match is low.

If the output of the tracking part 22 d, that is, the information onsmoothened movement(s) of the moving object(s), is accurate, theautonomous driving output reliance is higher compared with if theinformation is inaccurate. In this case, for example, if the location(s)of the moving object(s) is estimated based on the information on themoving object(s) detected and a deviation of the estimated location froman actual location(s) of the moving object(s) is small, the output ofthe tracking part 22 d is more accurate compared with if the deviationis large.

If the output of the integrated recognizing part 22 e, that is, theintegrated outside environment information, is accurate, the autonomousdriving output reliance is higher compared with if this information isinaccurate. In this case, for example, if a consistency of the output ofthe localizing part 22 a, the output of the object detecting part 22 b,the output of the moving/stationary classifying part 22 c, and theoutput of the tracking part 22 d is high, the output of the integratedrecognizing part 22 e is more accurate compared with if the consistencyis low. For example, there may be a case where the object detecting part22 b detects a certain object as a pedestrian while themoving/stationary classifying part 22 c detects the object in questionas a stationary object. In such a case, it is judged that theconsistency of the output of the object detecting part 22 b and theoutput of the moving/stationary classifying part 22 c is low. Note that,such inconsistency is liable to occur if the object in question is aposter including a photo of a person.

If the output of the traffic signal status recognizing part 22 f, thatis, the information on the state of the traffic signal, is accurate, theautonomous driving output reliance is higher compared with if thisinformation is inaccurate. In this case, for example, a dimension of thetraffic signal which is predicted to be detected from the currentlocation of the host vehicle is calculated based on the current locationof the host vehicle and road map, and if a deviation between thecalculated dimension and a dimension of the traffic signal actuallydetected by the front camera is small, the output of the traffic signalstatus recognizing part 22 f is more accurate compared with if thedeviation is large.

In another embodiment (not shown), for example, a dangerousness of thevehicle when assuming the vehicle cannot run in accordance with thetarget path is calculated. If this dangerousness falls or is maintained,the reliance of the target path, that is, the reliance of the output ofthe judgment/path generating part 22 g, is higher compared with if thedangerousness increases.

Furthermore, as shown in FIG. 5, the output of the autonomous drivingcontrol part 22 is found based on the outputs of the distancemeasurement sensor, GPS receiving part, IMU, and front camera.Therefore, the reliance of the output of the autonomous driving controlpart 22 also depends on reliance of the outputs of the distancemeasurement sensor, GPS receiving part, IMU, and front camera.Therefore, in the first embodiment according to the present invention,the autonomous driving output reliance is calculated based on thereliance of the output of at least one of the distance measurementsensor, GPS receiving part, IMU, and front camera.

Furthermore, the autonomous driving output reliance also depends on theshape of the road over which the vehicle is running (for example, curvedor straight, curvature of curves, locations of intersections, mergingpoints, and branching points etc.) and the situation around the vehicle(for example, whether the vehicle is at an intersection, whether thevehicle is located around a train station, etc.). That is, for example,if a vehicle is running over a curve, there is a higher possibility thatthe output of the localizing part 22 a is inaccurate compared to if thevehicle is running over a straight portion. Therefore, it is estimatedthat the autonomous driving output reliance is low. Alternatively, alarge number of pedestrians and vehicles are likely present around atrain station and thus, if a vehicle is located around the trainstation, there is a higher possibility that the output of the objectdetecting part 22 b is inaccurate compared with if the vehicle is notlocated there and therefore it is predicted that the autonomous drivingoutput reliance is low. Therefore, in the first embodiment according tothe present invention, for example, the autonomous driving outputreliance is stored linked with map information in the map database 4 orthe road map in the storage device 5. The autonomous driving outputreliance is calculated based on the running location of the host vehicleon the map.

In addition, in the first embodiment according to the present invention,when the vehicle is actually running, the autonomous driving outputreliance calculated at this time is stored linked with the runninglocation of the host vehicle on the map. When the vehicle is nextrunning at that location, the autonomous driving output reliance linkedwith this location is calculated as the autonomous driving outputreliance at this time.

Note that, as explained above, if it is judged that autonomous drivingis difficult, the driver is requested to perform manual driving. In thefirst embodiment according to the present invention, if the autonomousdriving output reliance is lower than a predetermined constant lowerlimit value, it is judged that autonomous driving is difficult and thedriver is requested to perform manual driving.

On the other hand, the driver vigilance, as explained above, shows avigilance of the driver for the autonomous driving. That is, the drivervigilance shows to what extent the driver has prepared for manualdriving at the time of autonomous driving. Specifically, if the driverhas sufficiently prepared for manual driving, the driver vigilance ishigher compared with if the preparation is insufficient.

This driver vigilance is calculated based on the above-mentionedcondition of the driver. Specifically, for example, if a line of visionof the driver is directed to the front of the vehicle V, the drivervigilance is higher compared with if the line of vision of the driver isdirected to the sides. Alternatively, if a time during which the line ofvision of the driver is directed to the front of the vehicle V is longand a frequency by which the driver checks the side mirrors or backmirror is high, the driver vigilance is higher compared with if the timeduring which the line of vision of the driver is directed to the frontof the vehicle V is short or if the frequency by which the driver checksthe side mirrors or back mirror is low. If a time during which the lineof vision of the driver is directed to an object(s), in particular amoving object(s), is long, the driver vigilance is higher compared withif this time is short. If a frequency of blinking of the driver is high,the driver vigilance is higher compared with if the frequency ofblinking of the driver is low. If the driver is not crossing thedriver's arms, the driver vigilance is higher compared with if thedriver is crossing the driver's arms. If the driver is not engaged in asecond task, the driver vigilance is higher compared with if driver isengaged in the second task. Note that the driver vigilance also dependson a type and time of the second task performed by the driver. If thedriver is gripping the steering wheel, the driver vigilance is highercompared with if the driver is not gripping the steering wheel. If anoffset of the distribution of the sitting pressure of the driver issmall, the driver vigilance is higher compared with if the offset of thedistribution is large. Alternatively, if a deviation of the distributionof sitting pressure of the driver from a predetermined referencedistribution is small, the driver vigilance is higher compared with ifthe deviation is large. In one example, the reference distribution isconstant. In another example, the reference distribution is set inaccordance with the individual driver. If the back part of the driver'sseat is set closer to the vertical orientation, the driver vigilance ishigher compared with if the back part is tilted closer to the horizontalorientation. If a heart rate of the driver is high, the driver vigilanceis higher compared with if the heart rate of the driver is low.

If the action against the driver mentioned above is taken, the drivervigilance increases. In this case, an extent of increase of drivervigilance depends on a strength of the action against the driver. Thatis, if the action against the driver is strong, the driver vigilancegreatly increases. If the action against the driver is weak, the drivervigilance increases just slightly or does not change much at all. On theother hand, if no action against the driver is taken, the drivervigilance falls along with time, unless the driver takes an action whichincreases the driver vigilance spontaneously. Therefore, the drivervigilance can be controlled by controlling the action against thedriver.

Now then, in the first embodiment according to the present invention, ina region in which an operating point determined by the autonomousdriving output reliance and driver vigilance can fall, a plurality ofsub regions are defined by at least one boundary line extending so thatthe driver vigilance becomes higher as the autonomous driving outputreliance becomes lower. Further, part of the plurality of sub regions isset as a target sub region.

In the example shown in FIG. 6, in the region in which the operatingpoint can fall, three sub regions R1, R2, and R3 are defined by twoboundary lines B1 and B2 extending so that the driver vigilance becomeshigher as the autonomous driving output reliance becomes lower. Notethat, in FIG. 6, the autonomous driving output reliance of the ordinatebecomes higher as it goes upward, while the driver vigilance of theabscissa becomes higher as it goes left. The first boundary line B1 isextending at the side of the lower autonomous driving output relianceand lower driver vigilance, while the second boundary line B2 isextending at the side of the higher autonomous driving output relianceand higher driver vigilance. The first sub region R1 is located at theside of the lower autonomous driving output reliance and lower drivervigilance with respect to the first boundary line B1. The second subregion R2 is located between the first boundary line B1 and the secondboundary line B2. The third sub region R3 is located at the side ofhigher autonomous driving output reliance and higher driver vigilancewith respect to the second boundary line B2.

Further, one among the three sub regions R1, R2, and R3, specificallythe second sub region R2, is set as the target sub region RT. In FIG. 6,the target sub region RT is shown with dots. The sub regions R1, R2, andR3 and the target sub region RT are stored in advance in the form of amap shown in FIG. 6 in the ROM of the storage part 21. Note that, in theexample shown in FIG. 6, the boundary lines B1 and B2 are also includedin the target sub region RT.

Based on the above, in the first embodiment according to the presentinvention, the action control part 25 is configured to control astrength of the action against the driver so that the operating point ismaintained in the target sub region RT.

That is, if the operating point falls in the first sub region R1 asshown in FIG. 7 by P1, the strength of the action against the driver iscontrolled so that the operating point moves to the target sub regionRT. Specifically, the relatively strong action against the driver istaken to thereby increase the driver vigilance relatively larger, andtherefore the operating point is moved to the target sub region RT. Inthis case, if the action against the driver is excessively strong, theoperating point is moved to the third sub region R3, while if the actionagainst the driver is excessively weak, the operating point ismaintained in the first sub region R1 even if the driver vigilance isincreased. In the first embodiment according to the present invention,the strength of the action against the driver is selected so that theoperating point moves into the target sub region RT. Note that, even ifthe acting part 10 takes an action against the driver, the autonomousdriving output reliance does not change. Therefore, if the actionagainst the driver is taken, the driver vigilance changes while theautonomous driving output reliance is maintained.

On the other hand, if the operating point falls in the second sub regionR2 or target sub region RT as shown in FIG. 7 by P2, the strength of theaction against the driver is controlled so that the operating point ismaintained in the target sub region RT. Specifically, the relativelyweak action against the driver is taken and thereby the driver vigilanceis increased by a relatively small amount or is maintained. Therefore,the operating point is maintained in the target sub region RT.

If the operating point falls in the third sub region R3 outside of thetarget sub region RT as shown in FIG. 7 by P3, the strength of theaction against the driver is controlled so that the operating pointmoves into the target sub region RT. Specifically, if the operatingpoint falls in the third sub region R3, the strength of the actionagainst the driver is made zero, that is, the action against the driveris stopped. As explained above, if no action against the driver istaken, the driver vigilance falls along with the elapse of time.Therefore, the operating point then moves to the target sub region RT.In another embodiment according to the present invention (not shown), ifthe operating point falls in the third sub region R3, the very weakaction against the driver is taken so that the operating point moves tothe target sub region RT.

In this way, in the first embodiment according to the present invention,if the operating point moves to the first sub region R1 or third subregion R3 outside of the target sub region RT, the operating point isreturned to the target sub region RT. Note that the operating pointmoves from the target sub region RT to the first sub region R1 if theautonomous driving output reliance falls as shown in FIG. 8 by the arrowA1 or if the driver vigilance falls as shown in FIG. 8 by the arrow A2.On the other hand, the operating point moves from the target sub regionRT to the third sub region R3 if the autonomous driving output relianceincreases as shown in FIG. 8 by the arrow A3 or if the driver vigilanceincreases as shown in FIG. 8 by the arrow A4. Of course, the autonomousdriving output reliance and driver vigilance may change simultaneously.

If the operating point falls in the first sub region R1, it can beunderstood that the driver is excessively relaxed, while if theoperating point falls in the third sub region R3, the driver isexcessively tense. As opposed to this, if the operating point falls inthe second sub region R2 or the target sub region RT, it can beunderstood that the driver is suitably relaxed or tense. Therefore, inthe first embodiment according to the present invention, the strength ofthe action against the driver is controlled so that the driver is in asuitable condition.

Further, in the first embodiment according to the present invention, thetarget sub region RT is defined by the boundary lines B1 and B2extending so that the driver vigilance becomes higher as the autonomousdriving output reliance becomes lower, and thus the target sub region RTextends so that the driver vigilance becomes higher as the autonomousdriving output reliance becomes lower. For this reason, if theautonomous driving output reliance is high, maintaining the operatingpoint in the target sub region RT controls the driver vigilance to belower. This means that the driver is not liable to be excessively tense.On the other hand, if the autonomous driving output reliance is low, thedriver vigilance is controlled to be higher. Therefore, the driver isnot liable to become excessively relaxed. In this way, both if theautonomous driving output reliance is high and if it is low, the drivervigilance is suitably maintained.

In this way, in the first embodiment according to the present invention,as shown in FIG. 9, the action against the driver is made relativelystrong if the operating point falls in the first sub region R1, theaction against the driver is made relatively weak if the operating pointfalls in the target sub region RT, and no action against the driver ismade if the operating point falls in the third sub region R3.Accordingly, the action control part 25 is configured to control astrength of the action against the driver so as to differ according tothe sub region in which the operating point falls. Note that, thestrength of the action against the driver is, for example, stored inadvance in the ROM of the storage part 21 in the form of a map shown inFIG. 9.

FIG. 10 shows a routine showing a processing performed at the actioncontrol part 25 of the first embodiment according to the presentinvention. This routine is repeatedly performed every predetermined settime. Referring to FIG. 10, at step 100, the autonomous driving outputreliance is calculated. At the next step 101, the driver vigilance iscalculated. At the next step 102, the map of FIG. 6 is used to determinethe sub region to which the operating point, determined by theautonomous driving output reliance and driver vigilance, falls. At thenext step 103, the map of FIG. 9 is used to determine the strength ofthe action against the driver. At the next step 104, the action againstthe driver is taken with the calculated strength.

FIG. 11 and FIG. 12 show other examples of the boundary lines. In theexample shown in FIG. 6, the two boundary lines B1 and B2 are linesextending in parallel with each other. As opposed to this, in theexample shown in FIG. 11, the boundary lines B1 and B2 extend in anon-parallel relationship with each other. Specifically, the boundarylines B1 and B2 extend so as to separate from each other as theautonomous driving output reliance becomes higher and the drivervigilance becomes lower. In another example (not shown), the boundarylines B1 and B2 extend so as to approach each other as the autonomousdriving output reliance becomes higher and the driver vigilance becomeslower. On the other hand, in the example shown in FIG. 12, the boundarylines B1 and B2 are curved lines. Specifically, the boundary lines B1and B2 are upwardly convex curved lines. In another example (not shown),the boundary lines B1 and B2 are downwardly convex curved lines. In astill other example (not shown), one of the boundary lines B1 and B2 isan upwardly convex curved line and the other is a downwardly convexcurved line. In still another example (not shown), one of the boundarylines B1 and B2 is a straight line and the other is a curved line.

FIG. 13 to FIG. 16 show other examples of the boundary lines and targetsub regions. In the example shown in FIG. 6, in the region in which theoperating point can fall, three sub regions are defined by two boundarylines. As opposed to this, in the example shown in FIG. 13, two subregions R1 and R2 are defined by a single boundary line B in the regionin which the operating point can fall. The first sub region R1 islocated at the side of the lower autonomous driving output reliance andlower driver vigilance with respect to the boundary line B. The secondsub region R2 is located at the side of the higher autonomous drivingoutput reliance and higher driver vigilance with respect to the boundaryline B. Further, in the example shown in FIG. 13, the second sub regionR2 is set as the target sub region RT.

On the other hand, in the examples shown from FIG. 14 to FIG. 16, foursub regions R1, R2, R3, and R4 are defined in the region in which theoperating point can fall by three boundary lines B1, B2, and B3. Thefirst sub region R1 is located at the side of the lower autonomousdriving output reliance and lower driver vigilance with respect to thefirst boundary line B1. The second sub region R2 is located between thefirst boundary line B1 and the second boundary line B2. The third subregion R3 is located between the second boundary line B2 and the thirdboundary line B3. The fourth sub region R4 is located at the side of thehigher autonomous driving output reliance and higher driver vigilancewith respect to the third boundary line B3.

In the example shown in FIG. 14, the third sub region R3 is set as thetarget sub region RT. In the example shown in FIG. 15, the second subregion R2 is set as the target sub region RT. In the example shown inFIG. 16, a plurality of sub regions, that is, the second sub region R2and the third sub region R3, are set as the target sub region RT. Inthis regard, it may be understood that the sub regions R2 and R3 betweenthe first boundary line B1 and the third boundary line B2 are set as thetarget sub region RT.

Therefore, if expressing the examples shown in FIG. 6 and from FIG. 14to FIG. 16 generically, at least three sub regions are defined in theregion in which the operating point can fall, by at least two boundarylines, and at least one sub region between two boundary lines of theseboundary lines is set as the target sub region.

Note that, in the example shown in FIG. 13, for example, the relativelystrong action against the driver is taken if the operating point fallsin the first sub region R1 and the relatively weak action against thedriver is taken if the operating point falls in the second sub regionR2, to thereby maintain the operating point in the target sub region RT.On the other hand, in the example shown from FIG. 14 to FIG. 16, forexample, the relatively strong action against the driver is taken if theoperating point falls in the first sub region R1, the relatively weakaction against the driver is taken if the operating point falls in thesecond sub region R2, the very weak action against the driver is takenif the operating point falls in the third sub region R3, and no actionagainst the driver is taken if the operating point falls in the fourthsub region R4, to thereby maintain the operating point in the target subregion RT.

Furthermore, in the example shown in FIG. 14, if focusing on the firstsub region R1 and the second sub region R2 located at the side of thelower autonomous driving output reliance and the lower driver vigilancewith respect to the target sub region RT, the first sub region R1 doesnot adjoin the target sub region RT and is relatively far from thetarget sub region RT. Further, the second sub region R2 adjoins thetarget sub region RT and is relatively close to the target sub regionRT. On the other hand, as explained above, the relatively strong actionagainst the driver is taken if the operating point falls in the firstsub region R1, while the relatively weak action against the driver istaken if the operating point falls in the second sub region R2.

On the other hand, in the example shown in FIG. 15, if focusing on thethird sub region R3 and the fourth sub region R4 located at the side ofthe higher autonomous driving output reliance and the higher drivervigilance with respect to the target sub region RT, the third sub regionR3 adjoins the target sub region RT and is relatively close to thetarget sub region RT. Further, the fourth sub region R4 does not adjointhe target sub region RT and is relatively far from the target subregion RT. On the other hand, as explained above, the relatively strongaction against the driver is taken if the operating point falls in thethird sub region R3, while no action against the driver is taken if theoperating point falls in the fourth sub region R4.

Accordingly, it can be understood that, in the example shown in FIG. 14and FIG. 15, sub regions R2, R3 close to the target sub region RT andsub regions R1, R4 far from the target sub region are defined outsidethe target sub region RT by the boundary lines B1, B3, and the actioncontrol part 25 is configured to control a strength of the actionagainst the driver to differ between if the operating point falls in thesub regions R2 and R3 close to the target sub region and if theoperating point falls in the sub regions R1 and R4 farther from thetarget sub region, in a case where the operating point is outside thetarget sub region RT. Furthermore, in the example shown in FIG. 14, theaction control part 25 is configured to strengthen the action againstthe driver if the operating point falls in the sub region R1 fartherfrom the target sub region RT compared with if the operating point fallsin the sub region R2 closer to the target sub region RT, in a case wherethe operating point falls in the sub regions R1 and R2 at the side ofthe lower autonomous driving output reliance and lower driver vigilancewith respect to the target sub region RT. In the example shown in FIG.15, the action control part 25 is configured to weaken the actionagainst the driver if the operating point falls in the sub region R4farther from the target sub region RT compared with if the operatingpoint falls in the sub region R3 closer to the target sub region RT, ina case where the operating point falls in the sub regions R3 and R4 atthe side of the higher autonomous driving output reliance and higherdriver vigilance with respect to the target sub region RT. As a result,in both cases, the operating point outside the target sub region RT isquickly returned to the target sub region RT.

Note that, as explained above, in the first embodiment according to thepresent invention, if the autonomous driving output reliance is lowerthan the predetermined lower limit value, the driver is requested manualdriving. In other words, if the autonomous driving output reliance ishigher than the lower limit value, autonomous driving is continuedunless the driver starts manual driving spontaneously. However, theautonomous driving output reliance is liable to suddenly fall.Therefore, the operating point is liable to suddenly move to the firstsub region R1 outside of the target sub region RT. In this case, thedriver vigilance is liable to be excessively low and the driver isliable to have insufficiently prepared for manual driving. Therefore, inanother embodiment according to the present invention (not shown), eachtime the time during which autonomous driving is continued exceeds apreset time, the action against the driver is temporarily strengthened,to thereby increase the driver vigilance temporarily. As a result, evenif the autonomous driving output reliance suddenly falls, the driver candeal with manual driving. The action against the driver in this case is,for example, a request of manual driving to the driver through the HMI7. Specifically, the driver is requested all or part of the operationsfor powering, braking, and steering the vehicle. Next, the autonomousdriving is resumed after the manual driving is performed for example fora certain time. Alternatively, the autonomous driving is resumed if thedriver makes an input operation to start autonomous driving.

In this regard, for example, if the driver is wearing sunglasses or thedriver is under a backlight condition, it is difficult for the drivercondition sensor 9 to detect the condition of the driver such as theline of vision of the driver. Therefore, it is liable to be impossibleto accurately calculate the driver vigilance. If it is impossible toaccurately calculate the driver vigilance, it is not possible toaccurately determine the operating point and not possible to accuratelydetermine the sub region in which the operating point falls. On theother hand, even under such a situation, autonomous driving ispreferably continued. Therefore, in another embodiment according to thepresent invention (not shown), if it is not possible to accuratelycalculate the driver vigilance, autonomous driving is continued whiletaking a strong action against the driver. Therefore, the autonomousdriving is continued while the driver vigilance is maintained high. Inanother embodiment according to the present invention (not shown), if itis not possible to accurately calculate the driver vigilance, manualdriving is requested.

Another example of the action against the driver will be explained. Ifthe operating point moves from the target sub region RT to the first subregion R1, the action against the driver is controlled so that theoperating point returns to the target sub region RT. In this case, if adrop in the autonomous driving output reliance makes the operating pointmove to the first sub region R1, a type of action against the driver iscontrolled to differ depending on reasons for the drop in thisautonomous driving output reliance. That is, for example, if a drop inprecision of output of the localizing part 22 a causes the drop in theautonomous driving output reliance, an orientation of the back part ofthe driver's seat is changed to be closer to the vertical to therebyincrease the driver vigilance so that the driver immediately can startmanual driving. If a drop in precision of identification of a movingobject causes a drop in precision of output of the integratedrecognizing part 22 e to thereby cause the drop of the autonomousdriving output reliance, or if a drop in precision of output of thetracking part 22 d causes the drop in the autonomous driving outputreliance, the line of vision of the driver is guided so as to bedirected to a moving object(s). That is, for example, if the movingobject(s) is located in the right side of the driver, a light etc.,positioned at the right side of the driver, included in the acting part10 is turned on or blinked. If too many moving objects cause a drop inprecision of detection of the moving/stationary classifying part 22 c tothereby cause the drop in the autonomous driving output reliance, forexample, a visual action, or visual action and audio action are taken sothat the driver can immediately start manual driving. This is because amere guiding of the line of vision of the driver is insufficient. If adrop in precision of output of the object detecting part 22 b causes thedrop in the autonomous driving output reliance, the driver isimmediately requested manual driving. The drop in precision of theoutput of the object detecting part 22 b is very likely due to abreakdown in the external sensor 1, etc. and continuation of autonomousdriving would be difficult.

Next, a second embodiment according to the present invention will beexplained. Below, what is different from the first embodiment accordingto the present invention will be explained.

FIG. 17 shows a block diagram of an autonomous driving control systemfor a vehicle of the second embodiment according to the presentinvention. Referring to FIG. 17, the electronic control unit 20 isfurther provided with a target vigilance calculating part 30 andvigilance deviation calculating part 31.

The target vigilance calculating part 30 is configured to calculate alower limit target vigilance which is a lower limit target value of thedriver vigilance, based on the autonomous driving output reliance. Thislower limit target vigilance becomes lower as the autonomous drivingoutput reliance becomes higher, as shown in FIG. 18. The lower limittarget vigilance is stored in advance in the form of a map shown in FIG.18 in the ROM of the storage part 21.

Referring again to FIG. 17, the vigilance deviation calculating part 31is configured to calculate a vigilance deviation which is a deviation ofthe driver vigilance from the lower limit target vigilance. In thesecond embodiment according to the present invention, the vigilancedeviation is expressed in the form of a difference (drivervigilance-lower limit target vigilance). In another embodiment accordingto the present invention (not shown), the vigilance difference isexpressed in the form of a ratio (vigilance deviation=drivervigilance/lower limit target vigilance).

Based on the above, in the second embodiment according to the presentinvention, the action control part 25 is configured to control astrength of the action against the driver so that the driver vigilanceis maintained equal to or higher than the lower limit target vigilanceand the strength differs according to the vigilance deviation. This willbe explained with reference to FIG. 19.

In FIG. 19, PX shows an operating point if the autonomous driving outputreliance is DRX and the driver vigilance is DVX. Further, LVL shows aline obtained by connecting the lower limit target vigilances determinedin accordance with the autonomous driving output reliance. As shown inFIG. 19, the lower limit target vigilance if the autonomous drivingoutput reliance is DRX is DVL. Therefore, in the second embodimentaccording to the present invention, the strength of the action againstthe driver is controlled so that the driver vigilance becomes equal toor higher than DVL.

As a result, the driver vigilance is controlled to be low if theautonomous driving output reliance is high, while the driver vigilanceis controlled to be high if the autonomous driving output reliance islow. Therefore, the driver vigilance is maintained suitable both if theautonomous driving output reliance is high and if it is low.

Further, the vigilance deviation at this time is (DVX-DVL). In thesecond embodiment according to the present invention, the strength ofthe action against the driver is controlled so as to differ inaccordance with this vigilance deviation. Specifically, the actionagainst the driver is controlled to be stronger if the vigilancedeviation is small compared to if the vigilance deviation is large.

That is, in the second embodiment according to the present invention, asshown in FIG. 20, the action against the driver is controlled to becomestronger as the vigilance deviation becomes smaller. The strength of theaction against the driver is stored in advance in the form of a mapshown in FIG. 20 in the ROM of the storage part 21. As opposed to this,in another embodiment according to the present invention, as shown inFIG. 21, if the vigilance deviation is a positive value or zero, theaction against the driver is controlled to zero, that is, the actionagainst the driver is stopped, while if the vigilance deviation is anegative value, the action against the driver is controlled to becomestronger as the vigilance deviation becomes smaller. Note that thevigilance deviation is a negative value if the driver vigilance is lowerthan the lower limit target vigilance, while the vigilance deviation isa positive value if the driver vigilance is higher than the lower limittarget vigilance.

As a result, if the driver vigilance is lower than the lower limittarget vigilance, the driver vigilance is quickly controlled to be equalto or higher than the lower limit target vigilance, while if the drivervigilance is equal to or higher than the lower limit target vigilance,the driver vigilance is reliably maintained to be equal to or higherthan the lower limit target vigilance.

FIG. 22 shows a routine showing a processing performed at the actioncontrol part 25 of the second embodiment according to the presentinvention. This routine is repeatedly performed every predetermined settime. Referring to FIG. 22, at step 200, the autonomous driving outputreliance is calculated. At the next step 201, the driver vigilance iscalculated. At the next step 202, the lower limit target vigilance iscalculated using, for example, the map of FIG. 18. At the next step 203,the vigilance deviation is calculated. At the next step 204, thestrength of the action against the driver is determined using the map ofFIG. 20. At the next step 205, the action against the driver is taken bythe calculated strength.

Note that, in the example shown in FIG. 6, it is possible to understandthat the strength of the action against the driver is controlled so thatthe driver vigilance is maintained to be equal to or higher than adriver vigilance expressed by the boundary line B1 and is maintained tobe equal to or lower than a driver vigilance expressed by the boundaryline B2. Taking the above into account, the boundary line B1 correspondsto a lower limit target of the driver vigilance or a lower limit targetvigilance, while the boundary line B2 corresponds to an upper limittarget of the driver vigilance or an upper limit target vigilance.Therefore, in another embodiment according to the present invention (notshown), the target vigilance calculating part 30 is configured tocalculate the upper limit target of the driver vigilance or the upperlimit target vigilance based on the autonomous driving output reliance.The upper limit target vigilance becomes higher as the autonomousdriving output reliance becomes lower. The action control part 25 isconfigured to control the strength of the action against the driver sothat the driver vigilance is maintained to be equal to or higher thanthe lower limit target vigilance and to be equal to or lower than theupper limit target vigilance and that the strength differs according tothe vigilance deviation.

In this regard, if referring to a time during which autonomous drivingcan be continued as a possible autonomous driving duration, theautonomous driving output reliance is higher if the possible autonomousdriving duration is long compared to if the possible autonomous drivingduration is short. On the other hand, if referring to a time requiredfor the driver to start manual driving as a required driving switchingtime, the driver vigilance is higher if the required driving switchingtime is short compared to if the required driving switching time islong. Here, considering smoothly switching from autonomous driving tomanual driving, it is preferable that the required driving switchingtime is equal to or shorter than the possible autonomous drivingduration. Therefore, if considering that the required driving switchingtime corresponds to the lower limit target vigilance, maintaining thedriver vigilance to be equal to or higher than the lower limit targetvigilance corresponds to maintaining the required driving switching timeequal to or shorter than the possible autonomous driving duration. Thatis, in the second embodiment according to the present invention, thestrength of the action against the driver is controlled so that therequired driving switching time is maintained to be equal to or shorterthan the possible autonomous driving duration.

Next, a third embodiment according to the present invention will beexplained. Below, what is different from the second embodiment accordingto the present invention will be explained.

FIG. 23 shows a block diagram of an autonomous driving control systemfor a vehicle of the third embodiment according to the presentinvention. Referring to FIG. 23, the autonomous driving control systemfor a vehicle is further provided with a display part 40 which thedriver can view. The display part 40 is provided with a display fordisplaying, for example, image information. In the third embodimentaccording to the present invention, the display part 40 and HMI 7 areprovided with a common display. In another embodiment according to thepresent invention (not shown), the display part 40 and HMI 7 areprovided with separate displays.

On the other hand, the electronic control unit 20 is further providedwith a display control part 50 configured to control the display part 40to simultaneously display the autonomous driving output reliance anddriver vigilance at the display part 40.

FIG. 24 shows one example of the display on the display part 40. Asshown in FIG. 24 by 41 r, the autonomous driving output reliance isdisplayed on the display part 40 to direct from a first end portion 43 atoward a second end portion 43 b along a first axial line 42 a as theautonomous driving output reliance becomes higher. Specifically, theautonomous driving output reliance is displayed by a plurality of blocks44 r arranged along the first axial line 42 a between the first endportion 43 a and the second end portion 43 b. These blocks 44 r are forexample displayed in a lit up state or extinguished state. As theautonomous driving output reliance becomes higher, the number of blocks44 r displayed lit up increases in order from the first end portion 43 aside. In the example shown in FIG. 24, the blocks 44 r displayed lit upare drawn with hatching, while the blocks 44 r displayed extinguishedare drawn by broken lines. Therefore, in the example shown in FIG. 24,the display part 40 shows the autonomous driving output reliance isstage 4 in the seven stages.

On the other hand, as shown in FIG. 24 by 41 v, the driver vigilance isdisplayed on the display part 40 to direct from the second end portion43 b toward the first end portion 43 a along the first axial line 42 aas the driver vigilance becomes higher. Specifically, the drivervigilance is displayed by the plurality of blocks 44 v arranged alongthe first axial line 42 a between the first end portion 43 a and thesecond end portion 43 b. These blocks 44 v are for example displayed inthe lit up state or extinguished state. As the driver vigilance becomeshigher, the number of blocks 44 v displayed lit up is increased in orderfrom the second end portion 43 b side. Note that, in the example shownin FIG. 24, the blocks 44 v displayed lit up are drawn with hatching,while the blocks 44 v displayed extinguished are drawn by broken lines.Therefore, in the example shown in FIG. 24, the display part 40 showsthe driver vigilance is stage 4 in the seven stages.

Furthermore, if the driver vigilance is equal to the lower limit targetvigilance, the autonomous driving output reliance and driver vigilanceare displayed on the display part 40 so that the displayed autonomousdriving output reliance 41 r and the displayed driver vigilance 41 vcoincide with each other when viewed in a direction of a second axialline 42 b vertical to the first axial line 42 a. In the example shown inFIG. 24, the displayed autonomous driving output reliance and thedisplayed driver vigilance coincide with each other viewed in the secondaxial line 42 b direction. This is for the following reason.

FIG. 25 shows a case where the driver vigilance is lower than the caseshown in FIG. 24. Therefore, FIG. 25 shows the case where the drivervigilance is lower than the lower limit target vigilance. In this case,as shown in FIG. 25 by X, viewed in the second axial line 42 bdirection, the displayed autonomous driving output reliance 41 r and thedisplayed driver vigilance 41 v do not overlap.

As opposed to this, FIG. 26 shows a case where the driver vigilance ishigher than the case shown in FIG. 24. Therefore, FIG. 26 shows the casewhere the driver vigilance is higher than the lower limit targetvigilance. In this case, as shown in FIG. 26 by Y, viewed in the secondaxial line 42 b direction, the displayed autonomous driving outputreliance 41 r and the displayed driver vigilance 41 v overlap.

That is, the displayed autonomous driving output reliance 41 r and thedisplayed driver vigilance 41 v overlap if the driver vigilance is equalto or higher than the lower limit target vigilance, while the displayedautonomous driving output reliance 41 r and the displayed drivervigilance 41 v do not overlap if the driver vigilance is lower than thelower limit target vigilance. Therefore, if displaying the autonomousdriving output reliance and driver vigilance in a side-by-side manner asin the third embodiment according to the present invention, the drivercan easily recognize if the driver vigilance is equal to or higher thanthe lower limit target vigilance. For this reason, if the displayedautonomous driving output reliance 41 r and the displayed drivervigilance 41 v do not overlap, it is possible for the driver to increasethe driver vigilance so that they overlap.

Note that, FIG. 27 shows a case where the autonomous driving outputreliance is lower than the case shown in FIG. 24. In this case, thelower limit target vigilance is high, and thus the driver vigilance hasto be high. On the other hand, FIG. 28 shows a case where the autonomousdriving output reliance is higher than the case shown in FIG. 24. Inthis case, the lower limit target vigilance is low, and thus the lowdriver vigilance is allowable.

FIG. 29 shows a routine showing a processing performed at the displaycontrol part 50 of the third embodiment according to the presentinvention. This routine is repeatedly performed at every predeterminedset time. Referring to FIG. 29, at step 300, the autonomous drivingoutput reliance is calculated. At the next step 301, the drivervigilance is calculated. At the next step 302, for example, the map ofFIG. 18 is used to calculate the lower limit target vigilance. At thenext step 303, the autonomous driving output reliance and drivervigilance are displayed on the display part 40.

FIG. 30 shows another example of the display on the display part 40. Asshown in FIG. 30 by 41 r, the autonomous driving output reliance isexpressed by a bar along the first axial line 42 a continuouslyextending from the first end portion 43 a toward the second end portion43 b as the autonomous driving output reliance becomes higher. In thiscase, the bar is displayed so that a length of the bar becomes longer asthe autonomous driving output reliance becomes higher.

On the other hand, as shown in FIG. 30 by 41 v, the driver vigilance isdisplayed by a line segment, which moves from the second end portion 43b toward the first end portion 43 a along the first axial line 42 a asthe driver vigilance becomes higher. In this case, the line segment isdisplayed so as to be separated from the second end portion 43 b as thedriver vigilance becomes higher.

Furthermore, the autonomous driving output reliance and driver vigilanceare displayed on the display part 40 so that the displayed autonomousdriving output reliance 41 r and the displayed driver vigilance 41 vcoincide with each other when viewed in the direction of the secondaxial line 42 b vertical to the first axial line 42 a if the drivervigilance is equal to the lower limit target vigilance. Therefore, ifthe driver vigilance is equal to or higher than the lower limit targetvigilance, the displayed autonomous driving output reliance 41 r and thedisplayed driver vigilance 41 v overlap, while if the driver vigilanceis lower than the lower limit target vigilance, the displayed autonomousdriving output reliance 41 r and the displayed driver vigilance 41 v donot overlap. In the example shown in FIG. 30, the displayed autonomousdriving output reliance 41 r and the displayed driver vigilance 41 voverlap. This shows that the driver vigilance is equal to or higher thanthe lower limit target vigilance.

FIG. 31 shows still another example of display on the display part 40.In the example shown in FIG. 31, a time history of the autonomousdriving output reliance is displayed in the form of a line chart asshown by 41 r, while a time history of the driver vigilance is displayedin the form of a line chart as shown by 41 v.

FIG. 32 shows still another example of display on the display part 40.In the example shown in FIG. 32, the above-mentioned vigilance deviationis displayed as shown by 41 d. In this case, the vigilance deviation isdisplayed on the display part 40 to direct from the first end portion 43a toward the second end portion 43 b along the first axial line 42 a asthe vigilance deviation becomes larger. In the example shown in FIG. 32,if the vigilance deviation is equal to or larger than zero, the numberof blocks 44 d displayed lit up is increased as the vigilance deviationbecomes larger in order from the first end portion 43 a side. In otherwords, if the vigilance deviation is smaller than zero, that is, if thedriver vigilance is lower than the lower limit target vigilance, all ofthe blocks 44 d are displayed extinguished. As a result, whether thedriver vigilance is equal to or higher than the lower limit targetvigilance can be easily recognized by the driver.

It is possible to suitably maintain a driver vigilance regardless of anautonomous driving output reliance.

While the invention has been described by reference to specificembodiments chosen for purposes of illustration, it should be apparentthat numerous modifications could be made thereto, by those skilled inthe art, without departing from the basic concept and scope of theinvention.

This application claims the benefit of JP Application No. 2016-048834,the entire disclosure of which is incorporated by reference herein.

What is claimed is:
 1. An autonomous driving control system for avehicle which is able to switch between manual driving and autonomousdriving, the system comprising: a driver condition sensor for detectinga condition of a driver; an acting part able to take an action againstthe driver; and an electronic control unit comprising: an autonomousdriving control part configured to control the autonomous driving; areliance calculating part configured to calculate an autonomous drivingoutput reliance expressing a reliance of an output of the autonomousdriving control part; a vigilance calculating part configured tocalculate a driver vigilance expressing a vigilance of the driver forthe autonomous driving based on the condition of the driver detected bythe driver condition sensor; and an action control part configured tocontrol the acting part to control a strength of an action against thedriver, wherein, in a region in which an operating point determined bythe autonomous driving output reliance and the driver vigilance canfall, a plurality of sub regions are defined by at least one boundaryline extending so that the driver vigilance becomes higher as theautonomous driving output reliance becomes lower, and wherein the actioncontrol part is configured to control the strength of the action againstthe driver to differ in accordance with the sub region in which theoperating point falls.
 2. The autonomous driving control system for avehicle according to claim 1, wherein a part of the plurality of subregions is set as a target sub region, and wherein the action controlpart is configured to control the strength of the action against thedriver to maintain the operating point within the target sub region. 3.The autonomous driving control system for a vehicle according to claim2, wherein, in the region in which the operating point can fall, atleast three sub regions are defined by at least two boundary lines, andwherein a sub region between two boundary lines among the boundary linesis set as the target sub region.
 4. The autonomous driving controlsystem for a vehicle according to claim 2, wherein, in the regionoutside of the target sub region, the sub region close to the target subregion and the sub region far from the target sub region are defined bythe boundary lines, and wherein, if the operating point is outside ofthe target sub region, the action control part is configured to controlthe strength of the action against the driver to differ between if theoperating point falls in the sub region close to the target sub regionand if the operating point falls in the sub region far from the targetsub region.
 5. The autonomous driving control system for a vehicleaccording to claim 3, wherein, in the region outside of the target subregion, the sub region close to the target sub region and the sub regionfar from the target sub region are defined by the boundary lines, andwherein, if the operating point is outside of the target sub region, theaction control part is configured to control the strength of the actionagainst the driver to differ between if the operating point falls in thesub region close to the target sub region and if the operating pointfalls in the sub region far from the target sub region.
 6. An autonomousdriving control system for a vehicle which is able to switch betweenmanual driving and autonomous driving, the system comprising: a drivercondition sensor for detecting a condition of a driver; an acting partable to take an action against the driver; and an electronic controlunit comprising: an autonomous driving control part configured tocontrol the autonomous driving; a reliance calculating part configuredto calculate an autonomous driving output reliance expressing a relianceof an output of the autonomous driving control part; a vigilancecalculating part configured to calculate a driver vigilance expressing avigilance of the driver for the autonomous driving based on thecondition of the driver detected by the driver condition sensor; atarget vigilance calculating part configured to calculate a lower limittarget vigilance, which is a lower limit target of the driver vigilance,based on the autonomous driving output reliance, the lower limit targetvigilance becoming higher as the autonomous driving output reliancebecomes lower; a vigilance deviation calculating part configured tocalculate a vigilance deviation which is a deviation of the drivervigilance with respect to the lower limit target vigilance; and anaction control part configured to control the acting part to control astrength of an action against the driver, wherein the action controlpart is configured to control the strength of the action against thedriver so as to: maintain the driver vigilance equal to or higher thanthe lower limit target vigilance; and differ in accordance with thevigilance deviation.
 7. The autonomous driving control system for avehicle according to claim 6, wherein the action control part isconfigured to control the strength of the action against the driver tobecome stronger if the vigilance deviation is small compared to if thevigilance deviation is large.
 8. An autonomous driving control systemfor a vehicle which is able to switch between manual driving andautonomous driving, the system comprising: a driver condition sensor fordetecting a condition of a driver; a display part which the driver canview; and an electronic control unit comprising: an autonomous drivingcontrol part configured to control the autonomous driving; a reliancecalculating part configured to calculate an autonomous driving outputreliance expressing a reliance of an output of the autonomous drivingcontrol part; a vigilance calculating part configured to calculate adriver vigilance expressing a vigilance of the driver for the autonomousdriving based on the condition of the driver detected by the drivercondition sensor; and a display control part configured to control thedisplay part to display the autonomous driving output reliance and thedriver vigilance simultaneously on the display part.
 9. The autonomousdriving control system for a vehicle according to claim 8, wherein theelectronic control unit further comprises a target vigilance calculatingpart configured to calculate a lower limit target vigilance, which is alower limit target of the driver vigilance, based on the autonomousdriving output reliance, the lower limit target vigilance becominghigher as the autonomous driving output reliance becomes lower, andwherein the display control part is configured to: display on thedisplay part the autonomous driving output reliance to direct from afirst end portion toward a second end portion along a first axial lineas the autonomous driving output reliance becomes higher; display on thedisplay part the driver vigilance to direct from the second end portiontoward the first end portion along the first axial line as the drivervigilance becomes higher; and display on the display part the autonomousdriving output reliance and the driver vigilance so that the displayedautonomous driving output reliance and the displayed driver vigilancecoincide with each other when viewed in a direction of a second axialline vertical to the first axial line if the driver vigilance is equalto the lower limit target vigilance.